diff options
| -rw-r--r-- | qapi-schema-guest.json | 25 | ||||
| -rw-r--r-- | qapi/qmp-core.h | 1 | ||||
| -rw-r--r-- | qapi/qmp-registry.c | 14 | ||||
| -rw-r--r-- | qemu-ga.c | 334 | ||||
| -rw-r--r-- | qga/commands-posix.c | 170 | ||||
| -rw-r--r-- | qga/guest-agent-core.h | 3 |
6 files changed, 409 insertions, 138 deletions
diff --git a/qapi-schema-guest.json b/qapi-schema-guest.json index cf18876c57..d7a073ee70 100644 --- a/qapi-schema-guest.json +++ b/qapi-schema-guest.json @@ -296,14 +296,10 @@ # # @frozen: all non-network guest filesystems frozen # -# @error: failure to thaw 1 or more -# previously frozen filesystems, or failure to open a previously -# cached filesytem (filesystem unmounted/directory changes, etc). -# # Since: 0.15.0 ## { 'enum': 'GuestFsfreezeStatus', - 'data': [ 'thawed', 'frozen', 'error' ] } + 'data': [ 'thawed', 'frozen' ] } ## # @guest-fsfreeze-status: @@ -312,6 +308,9 @@ # # Returns: GuestFsfreezeStatus ("thawed", "frozen", etc., as defined below) # +# Note: This may fail to properly report the current state as a result of +# some other guest processes having issued an fs freeze/thaw. +# # Since: 0.15.0 ## { 'command': 'guest-fsfreeze-status', @@ -320,9 +319,10 @@ ## # @guest-fsfreeze-freeze: # -# Sync and freeze all non-network guest filesystems +# Sync and freeze all freezable, local guest filesystems # -# Returns: Number of file systems frozen on success +# Returns: Number of file systems currently frozen. On error, all filesystems +# will be thawed. # # Since: 0.15.0 ## @@ -332,10 +332,15 @@ ## # @guest-fsfreeze-thaw: # -# Unfreeze frozen guest fileystems +# Unfreeze all frozen guest filesystems +# +# Returns: Number of file systems thawed by this call # -# Returns: Number of file systems thawed -# If error, -1 (unknown error) or -errno +# Note: if return value does not match the previous call to +# guest-fsfreeze-freeze, this likely means some freezable +# filesystems were unfrozen before this call, and that the +# filesystem state may have changed before issuing this +# command. # # Since: 0.15.0 ## diff --git a/qapi/qmp-core.h b/qapi/qmp-core.h index 3bb3acb589..431ddbb337 100644 --- a/qapi/qmp-core.h +++ b/qapi/qmp-core.h @@ -38,6 +38,7 @@ void qmp_register_command(const char *name, QmpCommandFunc *fn); QmpCommand *qmp_find_command(const char *name); QObject *qmp_dispatch(QObject *request); void qmp_disable_command(const char *name); +void qmp_enable_command(const char *name); bool qmp_command_is_enabled(const char *name); char **qmp_get_command_list(void); diff --git a/qapi/qmp-registry.c b/qapi/qmp-registry.c index 25c89ad098..43d5cdeb64 100644 --- a/qapi/qmp-registry.c +++ b/qapi/qmp-registry.c @@ -40,18 +40,28 @@ QmpCommand *qmp_find_command(const char *name) return NULL; } -void qmp_disable_command(const char *name) +static void qmp_toggle_command(const char *name, bool enabled) { QmpCommand *cmd; QTAILQ_FOREACH(cmd, &qmp_commands, node) { if (strcmp(cmd->name, name) == 0) { - cmd->enabled = false; + cmd->enabled = enabled; return; } } } +void qmp_disable_command(const char *name) +{ + qmp_toggle_command(name, false); +} + +void qmp_enable_command(const char *name) +{ + qmp_toggle_command(name, true); +} + bool qmp_command_is_enabled(const char *name) { QmpCommand *cmd; diff --git a/qemu-ga.c b/qemu-ga.c index 74a1b02c68..216be39072 100644 --- a/qemu-ga.c +++ b/qemu-ga.c @@ -18,6 +18,7 @@ #ifndef _WIN32 #include <syslog.h> #include <sys/wait.h> +#include <sys/stat.h> #endif #include "json-streamer.h" #include "json-parser.h" @@ -41,6 +42,7 @@ #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0" #endif #define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid" +#define QGA_STATEDIR_DEFAULT "/tmp" #define QGA_SENTINEL_BYTE 0xFF struct GAState { @@ -56,10 +58,27 @@ struct GAState { GAService service; #endif bool delimit_response; + bool frozen; + GList *blacklist; + const char *state_filepath_isfrozen; + struct { + const char *log_filepath; + const char *pid_filepath; + } deferred_options; }; struct GAState *ga_state; +/* commands that are safe to issue while filesystems are frozen */ +static const char *ga_freeze_whitelist[] = { + "guest-ping", + "guest-info", + "guest-sync", + "guest-fsfreeze-status", + "guest-fsfreeze-thaw", + NULL +}; + #ifdef _WIN32 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data, LPVOID ctx); @@ -68,6 +87,15 @@ VOID WINAPI service_main(DWORD argc, TCHAR *argv[]); static void quit_handler(int sig) { + /* if we're frozen, don't exit unless we're absolutely forced to, + * because it's basically impossible for graceful exit to complete + * unless all log/pid files are on unfreezable filesystems. there's + * also a very likely chance killing the agent before unfreezing + * the filesystems is a mistake (or will be viewed as one later). + */ + if (ga_is_frozen(ga_state)) { + return; + } g_debug("received signal num %d, quitting", sig); if (g_main_loop_is_running(ga_state->main_loop)) { @@ -126,6 +154,8 @@ static void usage(const char *cmd) " %s)\n" " -l, --logfile set logfile path, logs to stderr by default\n" " -f, --pidfile specify pidfile (default is %s)\n" +" -t, --statedir specify dir to store state information (absolute paths\n" +" only, default is %s)\n" " -v, --verbose log extra debugging information\n" " -V, --version print version information and exit\n" " -d, --daemonize become a daemon\n" @@ -137,7 +167,8 @@ static void usage(const char *cmd) " -h, --help display this help and exit\n" "\n" "Report bugs to <mdroth@linux.vnet.ibm.com>\n" - , cmd, QGA_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT); + , cmd, QGA_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT, + QGA_STATEDIR_DEFAULT); } static const char *ga_log_level_str(GLogLevelFlags level) @@ -207,11 +238,171 @@ void ga_set_response_delimited(GAState *s) } #ifndef _WIN32 +static bool ga_open_pidfile(const char *pidfile) +{ + int pidfd; + char pidstr[32]; + + pidfd = open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR); + if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) { + g_critical("Cannot lock pid file, %s", strerror(errno)); + return false; + } + + if (ftruncate(pidfd, 0) || lseek(pidfd, 0, SEEK_SET)) { + g_critical("Failed to truncate pid file"); + goto fail; + } + sprintf(pidstr, "%d", getpid()); + if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) { + g_critical("Failed to write pid file"); + goto fail; + } + + return true; + +fail: + unlink(pidfile); + return false; +} +#else /* _WIN32 */ +static bool ga_open_pidfile(const char *pidfile) +{ + return true; +} +#endif + +static gint ga_strcmp(gconstpointer str1, gconstpointer str2) +{ + return strcmp(str1, str2); +} + +/* disable commands that aren't safe for fsfreeze */ +static void ga_disable_non_whitelisted(void) +{ + char **list_head, **list; + bool whitelisted; + int i; + + list_head = list = qmp_get_command_list(); + while (*list != NULL) { + whitelisted = false; + i = 0; + while (ga_freeze_whitelist[i] != NULL) { + if (strcmp(*list, ga_freeze_whitelist[i]) == 0) { + whitelisted = true; + } + i++; + } + if (!whitelisted) { + g_debug("disabling command: %s", *list); + qmp_disable_command(*list); + } + g_free(*list); + list++; + } + g_free(list_head); +} + +/* [re-]enable all commands, except those explictly blacklisted by user */ +static void ga_enable_non_blacklisted(GList *blacklist) +{ + char **list_head, **list; + + list_head = list = qmp_get_command_list(); + while (*list != NULL) { + if (g_list_find_custom(blacklist, *list, ga_strcmp) == NULL && + !qmp_command_is_enabled(*list)) { + g_debug("enabling command: %s", *list); + qmp_enable_command(*list); + } + g_free(*list); + list++; + } + g_free(list_head); +} + +static bool ga_create_file(const char *path) +{ + int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR); + if (fd == -1) { + g_warning("unable to open/create file %s: %s", path, strerror(errno)); + return false; + } + close(fd); + return true; +} + +static bool ga_delete_file(const char *path) +{ + int ret = unlink(path); + if (ret == -1) { + g_warning("unable to delete file: %s: %s", path, strerror(errno)); + return false; + } + + return true; +} + +bool ga_is_frozen(GAState *s) +{ + return s->frozen; +} + +void ga_set_frozen(GAState *s) +{ + if (ga_is_frozen(s)) { + return; + } + /* disable all non-whitelisted (for frozen state) commands */ + ga_disable_non_whitelisted(); + g_warning("disabling logging due to filesystem freeze"); + ga_disable_logging(s); + s->frozen = true; + if (!ga_create_file(s->state_filepath_isfrozen)) { + g_warning("unable to create %s, fsfreeze may not function properly", + s->state_filepath_isfrozen); + } +} + +void ga_unset_frozen(GAState *s) +{ + if (!ga_is_frozen(s)) { + return; + } + + /* if we delayed creation/opening of pid/log files due to being + * in a frozen state at start up, do it now + */ + if (s->deferred_options.log_filepath) { + s->log_file = fopen(s->deferred_options.log_filepath, "a"); + if (!s->log_file) { + s->log_file = stderr; + } + s->deferred_options.log_filepath = NULL; + } + ga_enable_logging(s); + g_warning("logging re-enabled due to filesystem unfreeze"); + if (s->deferred_options.pid_filepath) { + if (!ga_open_pidfile(s->deferred_options.pid_filepath)) { + g_warning("failed to create/open pid file"); + } + s->deferred_options.pid_filepath = NULL; + } + + /* enable all disabled, non-blacklisted commands */ + ga_enable_non_blacklisted(s->blacklist); + s->frozen = false; + if (!ga_delete_file(s->state_filepath_isfrozen)) { + g_warning("unable to delete %s, fsfreeze may not function properly", + s->state_filepath_isfrozen); + } +} + static void become_daemon(const char *pidfile) { +#ifndef _WIN32 pid_t pid, sid; - int pidfd; - char *pidstr = NULL; pid = fork(); if (pid < 0) { @@ -221,20 +412,11 @@ static void become_daemon(const char *pidfile) exit(EXIT_SUCCESS); } - pidfd = open(pidfile, O_CREAT|O_WRONLY|O_EXCL, S_IRUSR|S_IWUSR); - if (pidfd == -1) { - g_critical("Cannot create pid file, %s", strerror(errno)); - exit(EXIT_FAILURE); - } - - if (asprintf(&pidstr, "%d", getpid()) == -1) { - g_critical("Cannot allocate memory"); - goto fail; - } - if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) { - free(pidstr); - g_critical("Failed to write pid file"); - goto fail; + if (pidfile) { + if (!ga_open_pidfile(pidfile)) { + g_critical("failed to create pidfile"); + exit(EXIT_FAILURE); + } } umask(0); @@ -249,15 +431,14 @@ static void become_daemon(const char *pidfile) close(STDIN_FILENO); close(STDOUT_FILENO); close(STDERR_FILENO); - free(pidstr); return; fail: unlink(pidfile); g_critical("failed to daemonize"); exit(EXIT_FAILURE); -} #endif +} static int send_response(GAState *s, QObject *payload) { @@ -495,9 +676,11 @@ VOID WINAPI service_main(DWORD argc, TCHAR *argv[]) int main(int argc, char **argv) { - const char *sopt = "hVvdm:p:l:f:b:s:"; - const char *method = NULL, *path = NULL, *pidfile = QGA_PIDFILE_DEFAULT; - const char *log_file_name = NULL; + const char *sopt = "hVvdm:p:l:f:b:s:t:"; + const char *method = NULL, *path = NULL; + const char *log_filepath = NULL; + const char *pid_filepath = QGA_PIDFILE_DEFAULT; + const char *state_dir = QGA_STATEDIR_DEFAULT; #ifdef _WIN32 const char *service = NULL; #endif @@ -513,12 +696,13 @@ int main(int argc, char **argv) { "blacklist", 1, NULL, 'b' }, #ifdef _WIN32 { "service", 1, NULL, 's' }, -#endif +#endif + { "statedir", 1, NULL, 't' }, { NULL, 0, NULL, 0 } }; int opt_ind = 0, ch, daemonize = 0, i, j, len; GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL; - FILE *log_file = stderr; + GList *blacklist = NULL; GAState *s; module_call_init(MODULE_INIT_QAPI); @@ -532,17 +716,14 @@ int main(int argc, char **argv) path = optarg; break; case 'l': - log_file_name = optarg; - log_file = fopen(log_file_name, "a"); - if (!log_file) { - g_critical("unable to open specified log file: %s", - strerror(errno)); - return EXIT_FAILURE; - } + log_filepath = optarg; break; case 'f': - pidfile = optarg; + pid_filepath = optarg; break; + case 't': + state_dir = optarg; + break; case 'v': /* enable all log levels */ log_level = G_LOG_LEVEL_MASK; @@ -568,14 +749,12 @@ int main(int argc, char **argv) for (j = 0, i = 0, len = strlen(optarg); i < len; i++) { if (optarg[i] == ',') { optarg[i] = 0; - qmp_disable_command(&optarg[j]); - g_debug("disabling command: %s", &optarg[j]); + blacklist = g_list_append(blacklist, &optarg[j]); j = i + 1; } } if (j < i) { - qmp_disable_command(&optarg[j]); - g_debug("disabling command: %s", &optarg[j]); + blacklist = g_list_append(blacklist, &optarg[j]); } break; } @@ -583,7 +762,7 @@ int main(int argc, char **argv) case 's': service = optarg; if (strcmp(service, "install") == 0) { - return ga_install_service(path, log_file_name); + return ga_install_service(path, log_filepath); } else if (strcmp(service, "uninstall") == 0) { return ga_uninstall_service(); } else { @@ -602,19 +781,78 @@ int main(int argc, char **argv) } } -#ifndef _WIN32 - if (daemonize) { - g_debug("starting daemon"); - become_daemon(pidfile); - } -#endif - s = g_malloc0(sizeof(GAState)); - s->log_file = log_file; s->log_level = log_level; + s->log_file = stderr; g_log_set_default_handler(ga_log, s); g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR); - s->logging_enabled = true; + ga_enable_logging(s); + s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen", + state_dir); + s->frozen = false; +#ifndef _WIN32 + /* check if a previous instance of qemu-ga exited with filesystems' state + * marked as frozen. this could be a stale value (a non-qemu-ga process + * or reboot may have since unfrozen them), but better to require an + * uneeded unfreeze than to risk hanging on start-up + */ + struct stat st; + if (stat(s->state_filepath_isfrozen, &st) == -1) { + /* it's okay if the file doesn't exist, but if we can't access for + * some other reason, such as permissions, there's a configuration + * that needs to be addressed. so just bail now before we get into + * more trouble later + */ + if (errno != ENOENT) { + g_critical("unable to access state file at path %s: %s", + s->state_filepath_isfrozen, strerror(errno)); + return EXIT_FAILURE; + } + } else { + g_warning("previous instance appears to have exited with frozen" + " filesystems. deferring logging/pidfile creation and" + " disabling non-fsfreeze-safe commands until" + " guest-fsfreeze-thaw is issued, or filesystems are" + " manually unfrozen and the file %s is removed", + s->state_filepath_isfrozen); + s->frozen = true; + } +#endif + + if (ga_is_frozen(s)) { + if (daemonize) { + /* delay opening/locking of pidfile till filesystem are unfrozen */ + s->deferred_options.pid_filepath = pid_filepath; + become_daemon(NULL); + } + if (log_filepath) { + /* delay opening the log file till filesystems are unfrozen */ + s->deferred_options.log_filepath = log_filepath; + } + ga_disable_logging(s); + ga_disable_non_whitelisted(); + } else { + if (daemonize) { + become_daemon(pid_filepath); + } + if (log_filepath) { + s->log_file = fopen(log_filepath, "a"); + if (!s->log_file) { + g_critical("unable to open specified log file: %s", + strerror(errno)); + goto out_bad; + } + } + } + + if (blacklist) { + s->blacklist = blacklist; + do { + g_debug("disabling command: %s", (char *)blacklist->data); + qmp_disable_command(blacklist->data); + blacklist = g_list_next(blacklist); + } while (blacklist); + } s->command_state = ga_command_state_new(); ga_command_state_init(s, s->command_state); ga_command_state_init_all(s->command_state); @@ -648,13 +886,13 @@ int main(int argc, char **argv) ga_channel_free(ga_state->channel); if (daemonize) { - unlink(pidfile); + unlink(pid_filepath); } return 0; out_bad: if (daemonize) { - unlink(pidfile); + unlink(pid_filepath); } return EXIT_FAILURE; } diff --git a/qga/commands-posix.c b/qga/commands-posix.c index 087c3af7ff..d58730ad80 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -316,44 +316,40 @@ static void guest_file_init(void) #if defined(CONFIG_FSFREEZE) -static void disable_logging(void) -{ - ga_disable_logging(ga_state); -} - -static void enable_logging(void) -{ - ga_enable_logging(ga_state); -} - typedef struct GuestFsfreezeMount { char *dirname; char *devtype; QTAILQ_ENTRY(GuestFsfreezeMount) next; } GuestFsfreezeMount; -struct { - GuestFsfreezeStatus status; - QTAILQ_HEAD(, GuestFsfreezeMount) mount_list; -} guest_fsfreeze_state; +typedef QTAILQ_HEAD(, GuestFsfreezeMount) GuestFsfreezeMountList; + +static void guest_fsfreeze_free_mount_list(GuestFsfreezeMountList *mounts) +{ + GuestFsfreezeMount *mount, *temp; + + if (!mounts) { + return; + } + + QTAILQ_FOREACH_SAFE(mount, mounts, next, temp) { + QTAILQ_REMOVE(mounts, mount, next); + g_free(mount->dirname); + g_free(mount->devtype); + g_free(mount); + } +} /* * Walk the mount table and build a list of local file systems */ -static int guest_fsfreeze_build_mount_list(void) +static int guest_fsfreeze_build_mount_list(GuestFsfreezeMountList *mounts) { struct mntent *ment; - GuestFsfreezeMount *mount, *temp; + GuestFsfreezeMount *mount; char const *mtab = MOUNTED; FILE *fp; - QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) { - QTAILQ_REMOVE(&guest_fsfreeze_state.mount_list, mount, next); - g_free(mount->dirname); - g_free(mount->devtype); - g_free(mount); - } - fp = setmntent(mtab, "r"); if (!fp) { g_warning("fsfreeze: unable to read mtab"); @@ -377,7 +373,7 @@ static int guest_fsfreeze_build_mount_list(void) mount->dirname = g_strdup(ment->mnt_dir); mount->devtype = g_strdup(ment->mnt_type); - QTAILQ_INSERT_TAIL(&guest_fsfreeze_state.mount_list, mount, next); + QTAILQ_INSERT_TAIL(mounts, mount, next); } endmntent(fp); @@ -390,7 +386,11 @@ static int guest_fsfreeze_build_mount_list(void) */ GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err) { - return guest_fsfreeze_state.status; + if (ga_is_frozen(ga_state)) { + return GUEST_FSFREEZE_STATUS_FROZEN; + } + + return GUEST_FSFREEZE_STATUS_THAWED; } /* @@ -400,61 +400,61 @@ GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err) int64_t qmp_guest_fsfreeze_freeze(Error **err) { int ret = 0, i = 0; - struct GuestFsfreezeMount *mount, *temp; + GuestFsfreezeMountList mounts; + struct GuestFsfreezeMount *mount; int fd; char err_msg[512]; slog("guest-fsfreeze called"); - if (guest_fsfreeze_state.status == GUEST_FSFREEZE_STATUS_FROZEN) { - return 0; - } - - ret = guest_fsfreeze_build_mount_list(); + QTAILQ_INIT(&mounts); + ret = guest_fsfreeze_build_mount_list(&mounts); if (ret < 0) { return ret; } /* cannot risk guest agent blocking itself on a write in this state */ - disable_logging(); + ga_set_frozen(ga_state); - QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) { + QTAILQ_FOREACH(mount, &mounts, next) { fd = qemu_open(mount->dirname, O_RDONLY); if (fd == -1) { - sprintf(err_msg, "failed to open %s, %s", mount->dirname, strerror(errno)); + sprintf(err_msg, "failed to open %s, %s", mount->dirname, + strerror(errno)); error_set(err, QERR_QGA_COMMAND_FAILED, err_msg); goto error; } /* we try to cull filesytems we know won't work in advance, but other * filesytems may not implement fsfreeze for less obvious reasons. - * these will report EOPNOTSUPP, so we simply ignore them. when - * thawing, these filesystems will return an EINVAL instead, due to - * not being in a frozen state. Other filesystem-specific - * errors may result in EINVAL, however, so the user should check the - * number * of filesystems returned here against those returned by the - * thaw operation to determine whether everything completed - * successfully + * these will report EOPNOTSUPP. we simply ignore these when tallying + * the number of frozen filesystems. + * + * any other error means a failure to freeze a filesystem we + * expect to be freezable, so return an error in those cases + * and return system to thawed state. */ ret = ioctl(fd, FIFREEZE); - if (ret < 0 && errno != EOPNOTSUPP) { - sprintf(err_msg, "failed to freeze %s, %s", mount->dirname, strerror(errno)); - error_set(err, QERR_QGA_COMMAND_FAILED, err_msg); - close(fd); - goto error; + if (ret == -1) { + if (errno != EOPNOTSUPP) { + sprintf(err_msg, "failed to freeze %s, %s", + mount->dirname, strerror(errno)); + error_set(err, QERR_QGA_COMMAND_FAILED, err_msg); + close(fd); + goto error; + } + } else { + i++; } close(fd); - - i++; } - guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_FROZEN; + guest_fsfreeze_free_mount_list(&mounts); return i; error: - if (i > 0) { - qmp_guest_fsfreeze_thaw(NULL); - } + guest_fsfreeze_free_mount_list(&mounts); + qmp_guest_fsfreeze_thaw(NULL); return 0; } @@ -464,47 +464,61 @@ error: int64_t qmp_guest_fsfreeze_thaw(Error **err) { int ret; - GuestFsfreezeMount *mount, *temp; - int fd, i = 0; - bool has_error = false; + GuestFsfreezeMountList mounts; + GuestFsfreezeMount *mount; + int fd, i = 0, logged; + + QTAILQ_INIT(&mounts); + ret = guest_fsfreeze_build_mount_list(&mounts); + if (ret) { + error_set(err, QERR_QGA_COMMAND_FAILED, + "failed to enumerate filesystems"); + return 0; + } - QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) { + QTAILQ_FOREACH(mount, &mounts, next) { + logged = false; fd = qemu_open(mount->dirname, O_RDONLY); if (fd == -1) { - has_error = true; - continue; - } - ret = ioctl(fd, FITHAW); - if (ret < 0 && errno != EOPNOTSUPP && errno != EINVAL) { - has_error = true; - close(fd); continue; } + /* we have no way of knowing whether a filesystem was actually unfrozen + * as a result of a successful call to FITHAW, only that if an error + * was returned the filesystem was *not* unfrozen by that particular + * call. + * + * since multiple preceeding FIFREEZEs require multiple calls to FITHAW + * to unfreeze, continuing issuing FITHAW until an error is returned, + * in which case either the filesystem is in an unfreezable state, or, + * more likely, it was thawed previously (and remains so afterward). + * + * also, since the most recent successful call is the one that did + * the actual unfreeze, we can use this to provide an accurate count + * of the number of filesystems unfrozen by guest-fsfreeze-thaw, which + * may * be useful for determining whether a filesystem was unfrozen + * during the freeze/thaw phase by a process other than qemu-ga. + */ + do { + ret = ioctl(fd, FITHAW); + if (ret == 0 && !logged) { + i++; + logged = true; + } + } while (ret == 0); close(fd); - i++; } - if (has_error) { - guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_ERROR; - } else { - guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_THAWED; - } - enable_logging(); + ga_unset_frozen(ga_state); + guest_fsfreeze_free_mount_list(&mounts); return i; } -static void guest_fsfreeze_init(void) -{ - guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_THAWED; - QTAILQ_INIT(&guest_fsfreeze_state.mount_list); -} - static void guest_fsfreeze_cleanup(void) { int64_t ret; Error *err = NULL; - if (guest_fsfreeze_state.status == GUEST_FSFREEZE_STATUS_FROZEN) { + if (ga_is_frozen(ga_state) == GUEST_FSFREEZE_STATUS_FROZEN) { ret = qmp_guest_fsfreeze_thaw(&err); if (ret < 0 || err) { slog("failed to clean up frozen filesystems"); @@ -933,7 +947,7 @@ int64_t qmp_guest_fsfreeze_thaw(Error **err) void ga_command_state_init(GAState *s, GACommandState *cs) { #if defined(CONFIG_FSFREEZE) - ga_command_state_add(cs, guest_fsfreeze_init, guest_fsfreeze_cleanup); + ga_command_state_add(cs, NULL, guest_fsfreeze_cleanup); #endif ga_command_state_add(cs, guest_file_init, NULL); } diff --git a/qga/guest-agent-core.h b/qga/guest-agent-core.h index 304525d3c2..bbb8b9b125 100644 --- a/qga/guest-agent-core.h +++ b/qga/guest-agent-core.h @@ -32,3 +32,6 @@ void ga_disable_logging(GAState *s); void ga_enable_logging(GAState *s); void slog(const gchar *fmt, ...); void ga_set_response_delimited(GAState *s); +bool ga_is_frozen(GAState *s); +void ga_set_frozen(GAState *s); +void ga_unset_frozen(GAState *s); |